Flexible LED Light Arrays

ABSTRACT

Flexible LED light arrays particularly suitable for use in clothing and other articles are disclosed. The light arrays are disposed on flexible printed circuit boards (PCBs). The flexible PCBs include substantially sinusoidal metal contact traces, along which the LEDs are attached at an angle preselected to minimize stresses in the expected directions of bending. The flexible PCBs may have control electronics provided on separate, attachable control boards, which may be either flexible or rigid. The flexible LED light arrays may also be arranged in master-slave configurations with a number of arrays, in which one master control array or board is attached to a number of slave arrays and handles external communication for the slave arrays.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/824,876, filed May 17, 2013, the contents of which areincorporated by reference herein in their entirety.

This application is also related to a U.S. patent application entitled“Fabric-Encapsulated Light Arrays and Systems for Displaying Video onClothing,” given docket no. EG-1-US, and filed on the same date as thisapplication. The contents of that application are incorporated byreference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to clothing with LED light arrays and to systemsfor displaying video on clothing.

2. Description of Related Art

For many years, manufacturers have sought to incorporate lights intoclothing. Most commonly, the lights have been in the form oflight-emitting diodes (LEDs). U.S. Pat. No. 4,774,434 to Bennion is oneearly example of such a design, which includes a number of LEDs arrangedon a flexible substrate and encapsulated to protect them. Typically,these items of lighted clothing have been viewed as novelty items,although a few references, such as U.S. Patent Application PublicationNo. 2004/0047146 to Galoob et al., disclose lighted items of clothingthat can be used as safety gear.

While the concept of integrating an LED lighting system into a piece ofclothing is straightforward, its execution is not. Despite attempts overthe years, almost no lighted clothing products are regularly sold, andvery few products of this type have made it to market. A number of cost,engineering, and manufacturing issues have prevented most products fromsucceeding.

One of the major engineering issues is that clothing is very flexibleand is often subjected to a great deal of wear. Thus, any electronicelement embedded in a piece of clothing is subjected to wear, stresses,strains, and environmental exposure. Reliability becomes a problem;under adverse conditions, LEDs may simply “pop off” of a printed circuitboard, and control electronics may stop functioning.

U.S. Patent Application Publication No. 2011/0102304, which isincorporated by reference in its entirety herein, is the work of thepresent inventor and discloses LED lighting circuits for clothing thatuse rigid printed circuit boards. Rigid printed circuit boards mayimprove the survivability of the LEDs and the control electronics, butthey are not necessarily ideal for the very flexible environment ofclothing.

LED arrays that use flexible printed circuit boards would seem ideal foruse in clothing, but engineering them to survive the clothingenvironment and integrating them well with clothing are difficult.

SUMMARY OF THE INVENTION

One aspect of the invention relates to articles of clothing withembedded light arrays. The light arrays are encapsulated within fabricpockets in the articles of clothing, and the fabric pockets may be madeof conductive fabric, in order to shield the light arrays fromelectromagnetic interference. The arrays themselves comprise a number oflight-emitting diodes (LEDs) arrayed on a flexible printed circuit board(PCB), such as a polyimide PCB.

The PCB itself includes a number of features to reduce strain andimprove its ability to withstand flexure. For example, the LEDs arearrayed along substantially sinusoidal metal contact lines, and areoriented at an angle preselected to minimize stresses in an expecteddirection or directions of bending or flexure. In some embodiments, thatangle may be approximately 45° with respect to the horizontal. Contactbetween the traces and the LEDs is made in a rigid area directly beneatheach LED. Additionally, copper contact pads on various layers of the PCBare enlarged in order to resist delamination.

Another aspect of the invention relates to control and display systemsand methods for controlling LED light arrays in clothing. In systems andmethods according to this embodiment of the invention, a light array ora group of light arrays are in wireless communication with a controller,which may be a smartphone with an application or “app” allowing it tocommunicate with and control the light arrays. The controller is adaptedto direct the LED light arrays to display words, images, or videosubstantially in real time.

Yet another aspect of the invention relates to systems and methods fordistributing words, images, and video to a plurality of light arrays inclothing. A plurality of nearby light arrays may order and orientthemselves into a group such that each array is controlled to display aportion of a larger word, image, or video and the entire word, image, orvideo is displayed by the group. Words, images, and video may be sharedbetween users, and in some embodiments, an event manager or areacontroller may distribute words, images, and video to large numbers oflight arrays in clothing.

A further aspect of the invention relates to systems that integratemultiple LED light arrays. These systems include at least two lightarrays. Each of the at least two light arrays comprises a flexible PCBon which a number of LEDs are provided, connected to one another via aplurality of essentially sinusoidal contact traces. The LEDs arepositioned at an angle preselected to minimize stresses in expecteddirections of bending or flexure. A master control board is attached toor integrated with a first of the at least two light arrays. The mastercontrol board comprises at least one communications circuit and at leastone LED driver circuit to drive the LEDs on the first of the at leasttwo light arrays. A slave control board is attached between the first ofthe at least two light arrays and a second of the at least two lightarrays. Connected between the first and the second of the at least twolight arrays, the slave control board is in electrical communicationwith the master control board to receive instructions and comprises oneor more LED driver circuits to drive the LEDs on the second of the atleast two light arrays. In some embodiments, the master control boardand the slave control board are rigid PCBs.

Another further aspect of the invention relates to flexible PCB LEDlight arrays that may minimize the risk of damage to vias in bending.These PCB LED light arrays comprise a flexible PCB substrate. One ormore vias are provided that extend through at least some layers of theflexible PCB substrate. A component is mounted on a side of the flexiblePCB substrate opposite the one or more vias and provides a rigidifiedarea. The via is located within the rigidified area provided by thecomponent. The component itself is electrically unconnected and usuallyserves no purpose on the PCB other than to provide rigidity. Thecomponent may be, for example, a resistor, a capacitor, or an integratedcircuit package.

These and other aspects, features, and advantages of the invention willbe set forth in the description that follows.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The invention will be described with respect to the following drawingfigures, in which like numerals represent like features throughout theinvention, and in which:

FIG. 1 is a perspective view of a piece of clothing with an integratedLED light array encapsulated within a fabric pocket;

FIG. 2 is an exploded view of the fabric pocket and the LED array ofFIG. 1;

FIG. 3 is a schematic diagram of a first side of the LED array of FIG.1;

FIG. 4 is a schematic cross-sectional view of the printed circuit board(PCB) of the LED array, illustrating enlarged metal contact pads;

FIG. 5 is a schematic plan view of a PCB, illustrating a group of viasand an arrangement for selectively rigidifying the area around the viasto prevent damage;

FIG. 6 is a schematic diagram of the logic and communication componentsof the LED array of FIG. 1;

FIG. 7 is a diagram of a system for controlling light arrays accordingto one embodiment of the invention;

FIG. 8 is a side elevational view of a master-slave light arrayarrangement according to another embodiment of the invention;

FIG. 9 is a detailed side elevational view showing a portion of FIG. 8and illustrating one way of connecting two adjacent light arrays;

FIG. 10 is a side elevational view similar to the view of FIG. 9,illustrating another way of connecting two adjacent light arrays;

FIG. 11 is a top plan view of the connection of FIG. 10;

FIG. 12 is a top plan view illustrating the connection of a controlboard to a light array;

FIG. 13 is a side elevational view illustrating the control board andlight array of FIG. 12;

FIG. 14 is a top plan view of a light array connected to a control boardaccording to one embodiment of the invention;

FIG. 15 is a top plan view of a light array connected to a control boardaccording to another embodiment of the invention;

FIG. 16 is a top plan view of a plurality of light arrays connected to asingle control board

FIG. 17 is a perspective view illustrating a pair of suspenders withinstalled LED light arrays; and

FIG. 18 is a perspective view of a ball with installed LED light arrays.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a piece of clothing, generally indicatedat 10, according to one embodiment of the invention. The piece ofclothing 10 illustrated in FIG. 1 is a jacket or vest, althoughembodiments of the invention may include any type of clothing. In theillustrated embodiment, a light array 12 is attached to the clothing 10using hook-and-loop fastener, encapsulated within a fabric pocket 14. Inother embodiments, the light array 12 may be sewn or otherwiseintegrated into the clothing 10. As will be described below in moredetail, the light array 12 is an array of light-emitting diodes (LEDs)that are individually logically addressable, such that the array iscapable of displaying, words, shapes, patterns, or real-time video. Thelight array 12 of the illustrated embodiment includes 256 individualLEDs 22, although any number of LEDs 22 may be included.

FIG. 2 is an exploded view of the fabric pocket 14 and light array 12.In this embodiment, the fabric pocket 14 includes an underlayer 16 thatis positioned below the light array 12 and an upper fabric layer 18designed to be positioned on top of the light array 12. The upper fabriclayer 18 includes a number of openings 20 whose size, shape, and pitchare defined so as to allow the individual LEDs 22 of the light array 12can protrude through the upper fabric layer 18. The underlayer 16 andupper fabric layer 18 may be made of any type of fabric, and in someembodiments, there may be additional layers of fabric on top of orbeneath the upper fabric layer 18. In some embodiments, it may behelpful if the fabric layers 16, 18 are made of an electricallyconductive fabric. A fabric may be made conductive using anyconventional technique. As one example, a sheet of fabric may be coatedwith a conductive polymer. Electrically conductive fabric encapsulatingthe light array 12 may act as a Faraday cage, shielding the light array12 from external electromagnetic radiation and preventing any signals orradiation from the light array 12 from interfering with other elements.However, an electromagnetically transparent window is generally providedin the fabric pocket 14 to allow for communication with externaldevices, as will be explained below in more detail. The light array 12may be electrically grounded or anchored to the fabric pocket 14.

In many embodiments, a conductive adhesive may be used over the majorityof the surface area of the light array 12 to physically secure it to thefabric layers 16, 18 so that the fabric layers 16, 18 do not shiftrelative to the light array 12. The electromagnetically transparent orpermissive areas may be established, for example, by masking an area andusing nonconductive adhesive, rather than conductive adhesive, withinthe masked area. FIG. 2 illustrates two nonconductive areas 23, 25 thatare aligned on the upper fabric layer 18 and the lower fabric layer 16and establish the electromagnetically transparent window.

FIG. 3 is a schematic illustration of a first side of the light array12. The light array 12 comprises a flexible printed circuit board (PCB)13, for example, made of polyimide film, on which a plurality of LEDs 22are installed. The light array 12 includes a control circuit area 24which may be folded under the portion of the PCB 13 that carries theLEDs 22 so as to reduce the footprint of the light array 12.Additionally, the control circuit area 24 of the illustrated embodimentcontains no components on its upper side, which would allow anotherlight array 12 to be tiled over the control circuit area 24, so that twoadjacent arrays appear to be continuous. Other adaptations to minimizethe footprint of the light array 12 may be made; for example, the powercord 15 (best seen in FIG. 2) may exit from the rear of the array 12within its dimensions, rather than from one edge.

The light array 12 includes several features that improve its ability tohandle flexure and the resulting stresses and strains. As can be seen inFIG. 3, the LEDs 22 are arranged in rows and columns. Each row of LEDsincludes a metal contact trace 26 that is sinusoidal in shape. Thesinusoidal shape of the metal contact traces 26 provides strain relief.Additionally, physical and electrical contact between the LEDs 22, thePCB 13, and the metal contact traces 26 is made only within therigidified area directly beneath the LEDs 22.

The LEDs 22 themselves are oriented at an angle of about 45° withrespect to the horizontal in the illustrated embodiment. The orientationof the LEDs 22 may help to relieve stresses in bending. In otherembodiments, the orientation of the LEDs 22 may be chosen based on theinitial configuration of the light array 12 and the expected directionof bending.

On the PCB 13, metal contact pads make electrical contact withcomponents mounted on the PCB 13, including the LEDs 22. The metal usedfor the conductive pads is typically copper, although it may be anyother metal or conductive material. The general construction of vias andcontact pads is well known in the art, and any conventional arrangementsor configurations may be used.

FIG. 4 is a schematic cross-sectional view of a portion of the PCB 13,illustrating the arrangement of the conductive pads 15 and the coverlay17. In PCBs 13 according to embodiments of the invention, the dimensionsof the conductive pads 15, typically made of copper, are increased about0.1 to 0.15 mm on each side compared with the surface area of normalconductive contact pads on a comparable rigid PCB. Additionally, thecoverlay 17 encroaches a minimum of about 0.05 to 0.1 mm onto the padsfor adhesion.

The illustration of FIG. 4 schematically shows only two layers on oneside of the PCB 13. Because PCBs 13 generally have several layers, oftenon both sides of the PCB 13, if electrical contact is necessary betweenlayers, a via is usually used. Vias are holes in the PCB 13 that areplated with gold, copper, aluminum, or another conductive metal. Becausethey are holes, vias may act as stress concentrators when the PCB 13 isloaded in bending. Additionally, when the PCB 13 flexes around a via,the metal plating in the via may simply delaminate. Thus, in embodimentsof the invention, the PCB 13 may be designed to minimize the risk ofdamage to or because of the vias.

FIG. 5 is a schematic diagram of a portion of the PCB 13 illustrating agrouping of vias 19 and their respective metal contact traces 21. Inembodiments of the invention, when vias are necessary, it isadvantageous to group those vias 19 so that they are placed close to oneanother. It is also helpful if a stiffener or a passive component ismounted on the opposite side of the PCB 13. The footprint or outline 23of the passive component is shown in FIG. 5, and as is also shown, allof the vias 19 in the group are placed within the footprint 23 of thepassive component.

The passive component 23 may be a surface mount device (SMD), such as alarge resistor, capacitor, chip package, or other such component, andmay be soldered to the PCB 13 to connect it mechanically to the PCB.However, it should be understood that in most embodiments, this passivecomponent 23 will be electrically unconnected to the other components onthe PCB 13, and will serve no electrical purpose. Instead, its presenceand mounting on the PCB 13 simply provide mechanical reinforcement andrigidity in the area of the vias 19 and prevent bending. Moreover, usinga large, passive device may be cheaper, and from a manufacturabilitystandpoint, easier, than rigidifying the PCB 13 in a conventional way.However, in some embodiments, instead of a passive component 23, astiffener, such as a piece of FR4 board, may be adhered to the PCB 13.

In addition to vias for electrical connectivity, the PCB may have anynumber of through holes 27 (best seen in FIG. 3) drilled or otherwiseformed in it. Through holes 27 may be positioned, for example, betweenlines of LEDs 22, or anywhere else there is space, and may allow formore airflow through the PCBs, thus potentially making the pieces ofclothing 10 more comfortable to wear.

In other embodiments, certain other adaptations may be made. Forexample, the control circuit area 24 need not be on one end of the lightarray 12, and may instead be positioned at the center of the PCB 13,which may allow multiple PCBs 13 to be laid next to one another whileminimizing space between adjacent LEDs 22 from different PCBs 13.

Additionally, while the PCB 13 of the illustrated embodiment isrectangular with straight sides, that need not be its shape in allembodiments. For example, in some embodiments, one or more of the edgesmay be scalloped. Scalloped edges may allow two adjacent PCBs 13 to beplaced adjacent to and in registration with one another, and may alsohave certain other advantages. Of course, the PCB 13 need not berectangular, and could instead have any number of sides. For example, apentagonal, hexagonal, or septagonal PCB could be made in someembodiments of the invention, as will be described below in more detail.

FIG. 6 is a schematic diagram of the control electronics for the lightarray 12. The function of the light array 12 is controlled by amicrocontroller unit (MCU) 50, which draws power from an appropriatepower source 52. The MCU 50 may, for example be a Model PIC32MX1microprocessor from Microchip Technology (Chandler, Ariz., UnitedStates). The power source 52 would typically be a direct current (DC)power source, such as a battery or set of batteries, but in someembodiments, the ultimate power source may be a higher voltagealternating current (AC) source, coupled with a transformer/rectifier tobring the supplied power to acceptable DC voltage and current levels.

The MCU 50 is connected to a memory 54. In most embodiments, the memorywould be a solid-state memory, such as Flash memory. However, otherforms of memory may be used. The amount of memory in each light array 12will vary from embodiment to embodiment, depending on the capabilitiesof the array 12, the complexity of the video or patterns each isintended to show, the number of LEDs in the light array 12 and otherconventional factors. In the illustrated embodiment, with 256 LEDs inthe array, 64 megabits has been found to be adequate.

The MCU 50 is connected to the outside world and receives instructionsfrom external programming devices via a transceiver unit 56 that iscoupled to an antenna 58 of an appropriate configuration. In theillustrated embodiment, the transceiver unit 56 is a BLUETOOTH®transceiver unit capable of receiving instructions and transmittingfeedback. However, in other embodiments, other types of transceivers mayprovide different wireless and other communication capabilities. Forexample, conventional IEEE 802.11a/b/g/n WiFi transceivers may beincluded to provide higher bandwidth or longer-range communication, asmay conventional cellular chipsets and transceivers for wireless datacommunication using a cellular network. Although only one transceiver 56is shown in FIG. 6, the light array 12 may have any number oftransceivers 56 for different communication modalities. Of course, sometransceivers 56 may require more power than others, which would, inturn, require a larger power source 52. Although optional, the lightarray 12 may also include components like a GPS receiver 60.

The above assumes that the light array 12 will communicate wirelessly.This may simplify the construction of garments, because it reduces oreliminates the need to access individual light arrays 12 once they aresewn into or otherwise secured in their respective fabric pockets 14.However, in some cases, instead of or in addition to wirelesscommunications via transceivers 56, the light array 12 could alsoinclude a Universal Serial Bus (USB) port, or another kind of physicalconnector, for data transfer.

In order to activate and control the LEDs 22, the MCU 50 communicateswith a plurality of LED drivers 62, each of which controls a matrix ofLEDs 22. As is common, the LEDs 22 of the light array 12 are driven inscanned matrices, and each of the LED drivers 62 has a number of outputlines to control a matrix of LEDs. While not shown in the schematic viewof FIG. 6, there may be a number of components, such as transistors,that regulate the power going to the LEDs 22 and perform otherconventional and well-known functions.

In some embodiments, the videos, patterns, or words displayed by thelight array or arrays 12 may be permanently set in the firmware of thearrays 12. For example, where the light arrays 12 are used in uniformsor safety clothing, the arrays 12 could be configured to display one ofa pre-set number of words, such as “POLICE,” “FIRE,” “EMT,” “PARAMEDIC,”and the like. This could be done by providing a physical switchsomewhere in the article of clothing that the user manipulates to changethe display of the light array. Decorative patterns or words could alsobe permanently set in the firmware of the arrays 12. In theseembodiments, the words or video would generally be stored locally in thememory of the array 12.

However, in particularly advantageous embodiments of the invention, thecontroller that directs the light array or arrays 12 is external to thearticle of clothing and, as explained briefly above, communicates withit via a wireless communication protocol (BLUETOOTH, WiFi, etc.). Insome cases, the controller may be a dedicated piece of hardware,although in most embodiments, it may be more advantageous for thecontroller to be an application or “app” that is implemented on a moregeneral-purpose computing platform. For example, an application tocontrol one or more light arrays 12 may be implemented on a desktop orlaptop computer, on a tablet computer, or on a smartphone. Moregenerally, any computing device that can communicate with a light array12 and can run the application may be used.

In some cases, light arrays 12 may be made and sold in models ofdiffering capabilities, depending at least in some part, on theircommunications capabilities. For example, a basic embodiment of a lightarray may be sold with a number of pre-programmed, selectable words orpatterns available in memory, with a selector switch being used totoggle between the pre-programmed patterns. A more advanced embodimentmight include a USB connector and the ability to be programmed withuser-defined patterns. A “full-featured” version would include thewireless communication capabilities and other features described above.

FIG. 7 is a schematic diagram of a control system, generally indicatedat 100, for light arrays 12 embedded in clothing. In the illustration ofFIG. 7, four pieces of clothing 102, 104, 106, 108 are shown, each ofwhich has at least one light array 12 embedded in it. As shown, thepants 108 have two light arrays 12, one on each leg. Each light array 12may be assumed to have the components described above, although thenumber of LEDs in each array, and the pitch or spacing of those LEDs,may vary.

Typically, as shown in FIG. 7, each article of clothing 102, 104, 106,108 will have its own controller 110, 112, 114, 116. These controllers110, 112, 114, 116 may, in some embodiments, be dedicated devices.However, for purposes of this description, unless otherwise noted, thecontrollers 110, 112, 114, 116 may be assumed to be smartphone computingdevices, such as the Apple iPHONE® (Apple, Inc., Cupertino, Calif.,United States), or other general-purpose computing devices, runningsoftware applications that allow the devices to act as controllers 110,112, 114, 116. In a typical embodiment, each controller 110, 112, 114,116 would be “paired” with its respective light array 12 or article ofclothing 102, 104, 106, 108 in typical fashion using the Bluetoothshort-range communication protocol, although in many instances, onecontroller 110, 112, 114, 116 may be used to control more than onearticle of clothing 102, 104, 106, 108.

The controllers 110, 112, 114, 116 define what word, picture, or videois to be displayed on each of the light arrays 12 and for how long,process existing words, images, and videos in other formats and fromother sources to place them in a format appropriate for the light arrays12, and transmit the image or video data to the light arrays 12 in realtime. In some embodiments, the controller 110, 112, 114, 116 may beadapted to synchronize the transmission and display of certain words,images, or videos with sound, music, and other elements of anaudiovisual presentation.

In some cases, if there are multiple light arrays 12 under its control,a controller 110, 112, 114, 116 may break a single image or video intomultiple adjacent segments and display those adjacent image or videosegments on physically adjacent light arrays 12. For example, if thereare multiple light arrays 12 on a single piece of clothing 108, thecontroller 116 for that piece of clothing may process an incoming videosignal to break it into two adjacent pieces of video suitable forplaying on the adjacent arrays 12 of the piece of clothing 108. Acontroller 116 controlling more than one light array 12 may, of course,direct each light array 12 to play or display an entirely differentimage, video, or word.

The controllers 110, 112, 114, 116 may also perform conversion andoptimization tasks. For example, if a video or image was not createdspecifically for display on one of the light arrays 12, the controller110, 112, 114, 116 may resize or crop the video, may convert it tograyscale, and may perform gamma correction and other such tasks.

In some embodiments, the individual light arrays 12 and pieces ofclothing 102, 104, 106, 108 may be configured to automatically determineif neighboring arrays are present and, if so, to order themselves bydetermining where they are in a larger grouping of light arrays 12(i.e., by locating their nearest neighbors). Each array 12 may thenaccept and display an appropriate segment of a larger image, word, orvideo. Standard received signal strength indication (RSSI) techniquesand, if available, GPS data, can be used for this kind of ordering. Insome cases, the light arrays 12 may be adapted, e.g., by adjustingfirmware, such that only light arrays 12 from the same vendor, or soldunder the same brand by an OEM vendor, will cooperate to form largerdisplay groupings.

Proximity detection may also be used with respect to the controllers110, 112, 114, 116. For example, if two controllers 110, 112, 114, 116are physically near one another, the users of those controllers 110,112, 114, 116 may be given the option to share images, videos, or wordsfor display on their respective articles of clothing 102, 104, 106, 108.In some cases, this may be simplified such that, e.g., two nearby usersmay “bump” their smartphones together while running the controllerapplication and, in so doing, cause their light arrays 12 to display thesame or complementary patterns. Technologies for implementing thisfeature are well known, and typically rely on an accelerometer to detecta movement and BLUETOOTH® or near field communication (NFC) to transferthe appropriate data. Other kinds of movements and triggers may be usedto transfer information.

Although much of the above description concentrates on the use ofindividual controllers 110, 112, 114, 116 and their paired articles ofclothing 102, 104, 106, 108, in some embodiments, words, images, andvideo may be distributed to mass numbers of light arrays 12 by a masteror area controller 118 broadcasting over a communication network 120.

As one example, a number of patrons may be attending a sporting event ina stadium while wearing clothing 102, 104, 106, 108 that includes lightarrays 12. In each case, the users may decide, by changing softwaresettings using their controllers 110, 112, 114, 116, to receive anddisplay words, images, and patterns transmitted (for example, usingWiFi) by a master area controller 118 that is located in the stadium andis under the control of stadium, game, or team officials. Thus, a largenumber of adjacent patrons could be displaying the same message, or apart of a larger image, video or message.

As was noted briefly above, the controllers 110, 112, 114, 116 may beeither dedicated devices or more general-purpose computing devices, likesmart phones, that run software applications or apps that allow thosedevices to perform the functions attributed to them. As the term is usedhere, “software” refers to sets of machine-readable instructions thatare in a machine-readable form and that, when executed, cause themachine to perform the described tasks. The machine-readable medium maybe any type of non-transitory memory, including magnetic disks, opticaldisks, solid-state drives, programmable read-only memory, external orinternal FLASH drives, or any other known form of electronic storagemedium.

When software applications are used to create controller functionality,the software applications may be distributed with the light arrays 12 orarticles of clothing 102, 104, 106, 108, or they may be distributed viathird-party vendors, for example, specific to different types ofcomputing devices. For example, applications for Apple devices may bedistributed by Apple, Inc. through the iTUNES® store, and applicationsfor devices running the ANDROID® operating system may be distributed viathe ANDROID® store.

In the above description, it is assumed that each light array 12 has itsown control circuit area 24. Various approaches for reducing thefootprint of a light array 12 are described above, including placinghigher-profile components on the underside of the control circuit area24 and folding the control circuit area 24 under the main body of thelight array 12.

In many embodiments, it may be helpful to separate the control circuitsfrom the actual LED arrays, for manufacturability reasons, to reduce thefootprint of the device, or to increase versatility. Additionally, inthe embodiments of the light array 12 described above, each light array12 has its own communication chipset and is a separate node forcommunication purposes. While effective, that setup may complicatecommunication with multiple arrays 12.

FIG. 8 is a side elevational view of a master-slave set of light arrays,generally indicated at 200, according to another embodiment of theinvention. In the set of light arrays 200, a master light array 202 hascontrol circuits 203 in a control circuit area 204, including acommunication chipset for BLUETOOTH®, WiFi, and/or other modes ofcommunication; and an LED matrix driver. As shown, the master lightarray 202 is connected to a number of slave arrays 206. A master lightarray 202 may be connected to any number of slave arrays 206.

Each of the slave arrays 206 is connected to the master light array 202and/or to other slave arrays 206 by a controller board 208. Thecontroller board 208 would generally include much the same circuitry asthe control circuits 203 of the master light array 202. However, thecontroller boards 208 would generally not include transceivers orreceivers for external communication (e.g., via BLUETOOTH®). Instead,those features would typically be handled by the master light array 202.

The illustration of FIG. 8 is generic; as those of skill in the art willrealize, master light arrays 202 may be connected to slave arrays 206 inany number of ways. Connections can be made horizontally or verticallybetween adjacent boards 102, 206. Horizontally, high-density surfacemount device (SMD) connectors and flexible printed circuit (FPC)connectors may be used.

FIG. 9 is an enlarged side elevational view of an area of FIG. 8,illustrating the connection of a master light array 202. In theillustrated embodiment, a controller board 208 “bridges” between themaster light array 202 and one of the slave arrays 206 vertically, andis connected electrically and mechanically between the undersides of thetwo boards 202, 206 by a pair of high-density surface mount connectors210 that have corresponding male and female portions, one on each of theconnecting surfaces.

The side elevational view of FIG. 8 illustrates a mode of verticalconnection in which a bridge and LED array driver board 208 is connectedbetween the undersides of two slave arrays 206 by the use of adhesivepads and spacers 210. The bridge and LED array driver board 208, whichmay be a rigid PCB, contains the control circuitry to control and drivethe LEDs 22.

FIG. 10, a side elevational view, and FIG. 11, a top plan view,illustrate an alternate way of mechanically and electrically couplingLED array boards in embodiments of the invention. In the view of FIG.10, two LED array boards 300, 302, which contain LEDs 22 and contacttraces 26 but no active control circuits, may also be connected by meansof groups of vertically-extending pins 304 provided on a bridge andarray controller board 308. The pins 304 extend upward from thecontroller board 308 and through vias 310 or other types ofthrough-holes provided in the flexible boards 300, 302. These pins maybe, for example, 3-5 mm in height and spaced with a pitch of 0.050inches or 2 mm. The number of pins 304 that are used, and the number ofgroups of pins 304 will depend on the number of electrical signal linesneeded for connection, and the number of pins needed for a securemechanical connection. The pins 304 may be placed in groups of, e.g.,four, with the groups of pins 304 spaced evenly along the width of thejoint, as shown in FIG. 11. While the pins 304 connect two array boards300, 302, this type of connection may be used for other purposes aswell.

In the embodiments of FIGS. 8-11, the slave arrays 206, 300, 302 do notcontain their own control electronics. Instead, those electronics are oneither the master light array 202 or on separate controller boards 208,308. In some embodiments, for reasons of manufacturability andmodularity, all control electronics may be placed on separate PCBs,while PCBs containing LEDs contain only LEDs and contacts. This conceptis illustrated in FIGS. 12 and 13, which are, respectively, a top planview and a side elevational view of an LED array PCB 400 connected to acontrol board 402, in this case by a number of metal pins 404 thatprovide both mechanical and electrical connection.

The LED array PCB 400 includes LEDs 22 and contact traces 26. Thecontrol board 402 contains control electronics, generally indicated at406. As with other embodiments, the surface-mounted components on thecontrol board 402 are mounted to its underside, relative to the locationof the LEDs 22, in order to allow one LED array PCB 400 to be mountedimmediately adjacent to another without a gap.

The LED array PCB 400 would generally be a flexible PCB, as with otherembodiments of the invention. However, depending on the embodiment, thecontrol board 402 itself may be either a flexible PCB or a rigid PCB. Ifthe control board 402 is a rigid PCB, it may be, for example, an FR4PCB. While FIGS. 12 and 13 illustrate a vertical connection that usespins 404 to connect the control board 402 and the LED array PCB 400,that is only one way in which the mechanical and electrical connectionbetween the two components may be established. As will be describedbelow in more detail, in other embodiments, other types of connectorsmay be used, and horizontal or vertical connections may be made.

In FIGS. 12 and 13, because the LED array PCB 400 is a lone array, thecontrol board 402 would generally be a fully equipped master controlboard with communications, external I/O, and programmable capabilities,as described above. However, in situations like that illustrated in FIG.8, where a number of slaves are connected to a master, only one of thecontrol boards 402 need be fully equipped; the others may omitcommunication capabilities.

In the top plan view of FIG. 14, a flexible LED array PCB 500 isconnected to a control board 502 by means of a thin strip of theflexible PCB material 504 that carries electrical contacts and is, forexample, soldered to the control board 502. In the top plan view of FIG.15, a flexible PCB LED array 600 is connected to a control board 602 bymeans of a connector 604, such as an FPC connector. The connector 604connects to a complementary socket that is mounted on each component600, 602.

In the description above, a control board is attached on one side of aflexible PCB light array. However, in embodiments where the jointbetween the flexible PCB light array and the control is expected to besubjected to unusual bending stresses or loads, the joint of a singleflexible PCB light array, or the joint joining two adjacent flexible PCBlight arrays, may be “sandwiched” between two rigid boards, one of whichacts as the control board and one of which is a plain board made of,e.g., FR4 material. In that case, the two boards may be rivetedtogether, or secured in some other permanent fashion.

FIG. 16 is a top plan view of an arrangement according to yet anotherembodiment of the invention. In the illustration of FIG. 16, a singlecontrol board 702 is electrically and mechanically connected to, andcontrols, four different flexible LED array boards 704, 706, 708, 710.The manner of connection in FIG. 16 is the same as that shown in FIG.14—thin connecting portions 712, 714, 716, 718 of the respectiveflexible LED array boards 704, 706, 708, 710 are soldered to the controlboard 702. However, it should be understood that the manner ofconnection is not critical, and the arrangement of FIG. 16 could alsouse connectors, as in FIG. 15.

FIG. 16 also illustrates an aspect of the invention that was describedbriefly above: the flexible LED array boards 704, 706, 708, 710 may havedifferent shapes. In the illustration of FIG. 16, one board 704 isshaped as an oval, another board 706 is round, yet another board 710 isrectangular with rounded corners, and one board 708 is star-shaped. Theboards 704, 706, 708, 710 may have substantially any shape, and as wasnoted above, the orientations of the LEDs 22 may be altered depending onthe directions in which bending and loading are expected. Moreparticularly, if each of the boards 704, 706, 708, 710 is expected tobend in a different way in use, then the orientation of the LEDs on eachboard 704, 706, 708, 710 may be different. In some cases, as with thestar-shaped board 708 of FIG. 16, the orientations of LEDs 22 ondifferent areas of the board 708 may be different.

Although the above description focuses on the use of light arrays 12 inclothing, fabric-encapsulated light arrays according to embodiments ofthe invention may be included in essentially anything, and may beparticularly suited for flexible substrates. For example,fabric-encapsulated light arrays could be incorporated into backpacksand messenger bags.

In the above description, it is assumed that the light arrays 12 extendessentially in two dimensions and are generally flat, at least inneutral position. That need not be the case. For example, light arrays12 could be installed in belts, suspenders, and other items that includesignificant curvature in use, and in curved or flexed positions in otheritems. Light arrays 12 according to embodiments of the invention couldalso be used in curved chandelier fixtures and in other such designs.

One example of this is shown in FIG. 17, a perspective view illustratinga person wearing suspenders, generally indicated at 800, that includeLEDs 22. The LEDs 22 on the suspenders would be placed in flexible PCBsthat have the basic features described above with respect to otherembodiments. In some cases, the LEDs 22 on each suspender may be part ofthe same flexible LED array. However, because of the length of thesuspenders 800, in many embodiments, the suspenders 800 may use a numberof shorter flexible PCBs arranged immediately adjacent to one another inorder to create a continuous effect, using the techniques describedabove. Configurations using multiple PCBs may use the master/slaveconfigurations described above, although because of the flexibility ofthe suspenders 800, the control boards for the arrays might themselvesbe flexible.

FIG. 17 illustrates that the LEDs 22 in the front of the suspenders 800have the 45° angle to the horizontal that is preselected to reducestresses in all directions. This anticipates bending and flexure inrandom directions. However, as the suspenders 800 go over the shoulders,the bending of the arrays is generally in a single, known direction.Thus, as the LEDs reach the area that arcs over the shoulders, theirorientation may change to horizontal (with respect to the orientation ofFIG. 17), or to another orientation that reduces stress in thatparticular mode of bending.

In the illustration of FIG. 17, two rows of LEDs 22 are shown on each ofthe suspender braces for ease of illustration. However, the number ofLEDs 22 on each of the suspender braces is not limited, and in otherembodiments, the number and pitch or density of the LEDs 22 may beincreased, limited only by the ability of the control electronics toaddress and control the individual LEDs 22.

Much of the description above assumes that a flexible LED array has a“neutral” position that is generally flat, and that that array is flexedin use. That is certainly the typical situation when an LED array isincorporated into clothing. However, LED arrays according to embodimentsof the invention may be used more broadly, and in some situations, LEDarrays may be designed to be typically or permanently curved. Permanentcurvatures may be achieved in a number of ways, including by bending aninitially flat LED array. (Of course, in that case, the orientation ofthe LEDs 22 on the PCB 13 would be chosen for the direction of bending.)

In some embodiments, discrete and slightly curved or convex PCBs of apolygonal or other shape may be joined together to create continuouscurvature, or may be joined with other materials to create continuouscurvature. For example, FIG. 18 illustrates a ball 900. An outer layerof the ball 900 comprises a plurality of generally pentagonal segments902 containing flexible PCB light arrays of a corresponding pentagonalshape that carry LEDs 22. The segments 902 carrying LED arrays areconnected to plain hexagonal segments 904 to complete the ball 900,although in other embodiments, both pentagonal segments 902 andhexagonal segments 904 may carry LEDs 22. The control boards are notshown in the view of FIG. 19, but would generally be arranged underand/or to the sides of the active segments 902. Power and othernecessary elements would typically be located inside the ball or sphere.

While the invention has been described with respect to certainembodiments, the embodiments are intended to be illuminating, ratherthan limiting. Modifications and changes may be made within the scope ofthe invention.

What is claimed is:
 1. A system for linking and controlling multiplelight arrays, comprising: at least two light-emitting diode (LED)arrays, each of the LED arrays including a flexible printed circuitboard (PCB) having at least one metallization layer and at least onecovering layer, one or more contact traces defined on the at least onemetallization layer and extending from a control circuit area totraverse a length of the flexible PCB, and a plurality of light-emittingdiodes (LEDs) attached to the PCB along the contact traces such thateach of the plurality of LEDs is oriented at a defined angle withrespect to the horizontal, the defined angle chosen to minimizemechanical stresses in an expected direction of bending or flexure, suchthat electrical and physical contact between each of the plurality ofLEDs and one of the contact traces is made in a rigidified area definedby a footprint of the LED; master control circuits associated with oneof the plurality of LED arrays, the master control circuits including atleast one communication circuit and at least one first LED drivercircuit; and slave control boards connecting the LED arrays, each of theslave control boards having at least one second LED driver circuit, theslave control boards being in electrical communication with the mastercontrol circuits.
 2. The system of claim 1, wherein the master controlcircuits are integrated into one of the LED arrays.
 3. The system ofclaim 1, wherein the master control circuits are disposed on a separatePCB and are attached to one of the LED arrays.
 4. The system of claim 3,wherein the separate PCB comprises a flexible PCB.
 5. The system ofclaim 3, wherein the separate PCB comprises a rigid PCB.
 6. The systemof claim 3, wherein the separate PCB is attached to the one of the LEDarrays by sets of pins that connect the separate PCB mechanically andelectrically.
 7. The system of claim 3, wherein the separate PCB isattached to the one of the LED arrays by a connector.
 8. The system ofclaim 1, wherein the slave control boards are rigid PCBs.
 9. The systemof claim 1, wherein the slave control boards are flexible PCBs.
 10. Thesystem of claim 1, wherein the slave control boards are connectedbetween the LED arrays by sets of pins.
 11. The system of claim 1,wherein the slave control boards are connected between the LED arrays bysurface-mount connectors that extend between a rear side of each of theLED arrays and the slave control boards.
 12. The system of claim 1,wherein the one or more contact traces are substantially sinusoidal. 13.The system of claim 1, wherein the defined angle is about 45°.
 14. Aflexible light array, comprising: a flexible printed circuit board (PCB)substrate, the flexible PCB substrate having a plurality of layers; aplurality of light-emitting diodes (LEDs) disposed on the substrate; oneor more vias extending through at least some of the plurality of layersof the flexible PCB; a passive component installed on the flexible PCBsubstrate on a side opposite the one or more vias, such that the passivecomponent provides selective rigidity in a defined area, the passivecomponent being mechanically connected to the flexible PCB substrate butserving no electrical purpose; wherein the one or more vias are placedwithin the defined area in which the passive component provides theselective rigidity.
 15. The flexible light array of claim 14, whereinthe passive component comprises a resistor, a capacitor, or anintegrated circuit package.
 16. The flexible light array of claim 14,wherein the plurality of LEDs are attached along respective generallysinusoidal contact traces.
 17. The flexible light array of claim 14,wherein each of the plurality of LEDs is arranged at a preselected angleto minimize stresses in expected directions of bending.
 18. A flexibleLED light array with separable control circuits, comprising: a flexibleprinted circuit board (PCB) having at least one metallization layer andat least one covering layer, one or more contact traces defined on theat least one metallization layer and extending from a control circuitarea to traverse a length of the flexible PCB, and a plurality oflight-emitting diodes (LEDs) attached to the PCB along the contacttraces such that each of the plurality of LEDs is oriented at a definedangle with respect to the horizontal, the defined angle chosen tominimize mechanical stresses in an expected direction of bending orflexure, such that electrical and physical contact between each of theplurality of LEDs and one of the contact traces is made in a rigidifiedarea defined by a footprint of the LED; and control circuits provided ona separate PCB and connected mechanically and electrically to theflexible PCB, the control circuits including at least one or more LEDdrivers to drive the LEDs.
 19. The flexible LED light array of claim 18,wherein the separate PCB is connected to the flexible PCB by aconnecting structures selected from the group consisting of:surface-mount connectors, cable connectors, and vertical pins.
 20. Theflexible LED light array of claim 18, wherein the separate PCB is rigidor flexible.
 21. The flexible LED light array of claim 18, wherein thecontrol circuits further comprise one or more communication circuits forexternal input and output.